Charging apparatus for shaft furnaces



Sept. l5, 1959 H. ANDERssoN .ETAL 2,904,195

CHARGING APPARATUS FOR SHAFT FuRNAcEs 2 Sheets-Sheet 1 Filed March 14, 1956 Sept- 15, l959 H. ANDERssoN ETAL 2,904,195

CHRGING APPARATUS FOR SHAFT FURNACES Filed March 14, 1956 2 Sheets-Sheet 2 lNVENTORS HOLGER ANDERSSON LARS OLOF UHRUS ATTYs:

United States Patent fic 52,904,195' Patented Sept. 15, 1959 2,904,195 CHARGING APPARATUS FOR `SHAFT FURNACES Holger Andersson and Lars Olof Ulu-ns, Hofors, Sweden, assignbrs to Aktieb'olaget Svenska Kullagerfabriken, Goteborg, Sweden, a corporation of Sweden Application March 14, 1956, Serial No. 571,496 Claims priority,'application Sweden'March 18, 1955y 13 Claims. (Cl. 214-18) Charging apparatuses for shaft furnaces moving to and fro over the top opening of a shaft furnace in order to d1stribute the material in a layer over the whole opening are comparatively great distance and are liable to be broken -in falling. In devices of this kind it has therefore been necessary to use rubber belts inthe conveyors. vThe hot, corrosive gases which ascend from the shaft, however,

quickly destroy the rubber belts and the device must frequently 4be stopped for repairs. l

The present invention relates to a charging apparatus of the kind inwhich a conveyor device is adapted to perform a reciprocating movement over the top of the fur nace and which will be durable and which will deposit 4 or somewhat more. The speed of the motor axle may be about 65 R.P.M. and the diameter `of the roller 7 relative to the track of the cylinder upon which it rolls is such that the cylinder is caused to revolve at a speed of about l5 R.P.M. This rotation causes the pellets to pass through the cylinder slowly and evenly until the finally leave the cylinder at its outlet end. The rotation of the cylinder serves another important purpose, namely to smoothen the surfaces of the wet pellets in order to decrease the abrasion of the pellets during and after burning.

The cylinder 5 is caused to reciprocate in the following manner. A motor 16 mounted on the frame drives a pair of wheels 17 and 18 through a toothed wheel 19 mounted on the motor axle, a chain 20 and another toothed wheel 22 mounted on the axle 21 of the wheels 17 and 18. The frame 15 is also provided with another pair of wheels 23 and 24. The conveyor belt 4 is mounted on another trarnel 25 which is supported at one end by a pair of wheels'26-26 and at the other end by the frame 15 and thus participates in the movements of the latter. When the motor 16 is started the frame 15 and all parts mounted thereon are set in motion for example towards the left in the drawing whereby the outlet end of the cylinder 5 also moves towards the left over the top of the furnace and thereby spreads the pellets passing through the cylinder over the surface of the material in the furnace. The

cylinder 5 is made of steel and is thus more resistant to the charge gently and spread it over the stockline in a which communicates with a feeding device and the outlet end of which is adaptedto 'be located'over Ithe'top `of the furnace.. Y it One for-m of the inventionl as lapplied to a pelletizing furnace is illustrated in the accompanying drawings in which Fig. 1 is aside view of the device partly in section. Fig. 2 is a plan view and Figs. 3 and 4 are end views at III-III and IV--IV respectively in Fig. 1.

In Fig. l the numeral 1 designates the top of a pelletizing furnace to which concentrate in the form of raw i.e. wet pellets is fed from a rotating drum 2. From the drum the material is carried by a conveyor belt 3 to another conveyor belt 4 the further end of which is located within a cylinder 5 open at both ends. The material delivered from the rotary drum 2, e.g. pellets of concentrate, are conveyed to and delivered to the cylinder 5. The inlet end of the cylinder rests on a pair of rollers 6 and 7 respectively, of which the roller 7 is connected to the driving shaft of -a geared motor 11 through a shaft 10 and universal joints 8 and 9. The other end of the cylinder is supported by a pair of rollers 12 and 13. These are provided with flanges to retain the cylinder in proper axial position. The rollers 6, 7, 12 and 13 are mounted on axles carried in housings 14 on a frame 15. The rollers tare adjustable either vertically or laterally, for instance through adjustment of one or more of the housings 14 so that the inlet end of the cylinder 5 will be Somewhat higher than its outlet end. In charging mechanisms for pelletizing furnaces the difference in height between both ends of the cylinder may suitably be such that the inclination of the cylinder relative to the horizontal plane is about the action of the gases rising from the furnace than hitherto used conveying devices.

The wet pellets Should be distributed so that the distancecovered by the air flowing through the charge from the air inlets to the upper surface of the charge will as far las possible be equal in all sections. For this reason the pellets should not be distributed in a :dat layer but instead so that the upper surface of the charge has more or less the shape indicated by the line 27 in Fig. 3. For this purpose a ridge-shaped ydistributor 28 is provided at theutlet end of the cylinder. The distributor may be perforated or have slots to permit small sized particles of the charge to drop throughk the distributor and thus concentrate in the center of the charge. The remainder of the material rolls olf the sloping surfaces of the distributor and is distributed more or less to one side or the other as described in the following.

The distributor 28 is carried on an arm 29 which is fixed to a Vertical spindle 30 carried in suitable bearings in the frame 15. A cross bar 31 extending to both sides is xed to the spindle 30 and at each end thereof is fixed a Wire 32 and 33 respectively. The other ends of the wires are connected with the respective ends of another cross bar 34 which is fixed to a vertical spindle 35. Fixed to this spindle is an arm 36, one end of which is jointedly connected to an `arm 37 which is adjustably connected to one end of an arm 38, the other end of which is connected to a crank 39. The crank is preferably made so that its throw is adjustable within suitable limits. The crank is driven -by the motor 11 through a Worm gear (not shown) and `a chain 40. When the motor rotates power is transmitted through the chain 40 to the worm gear and the crank and further to the arm 38 and from this to the arm 37. This actuates the arm 36 to cause it to oscillate together with the spindle 35 and the cross bar 34. This movement is communicated through the wires 32 and 33 to the cross bar 31 which is thus also caused to oscillate, this motion being transmitted in a similar manner to the arm 29 which carries the distributor 28 and thus to the distributor itself. The distributor will thus move in `an arcuate path from side to `side of the top as the cylinder -5 is moved to and fro over the top. The pellets are thus deposited more or less along a sine curve, a greater or lesser part of the material 4being delivered to one side or the other depending on the lateral position for the time being of the distributor. cycle of the sidewise movement of the distributor is preferably such that it is not an even function of the cycle of the movement to and .fro over the top of the furnace of the charging device. There will thus be a certain phase-displacement of the sine curve at each stroke and the material will be evenly distributed. The amplitude of the sidewise stroke of the distributor can be altered as required by changing the throw of the crank 39. Through relative adjustment between the arms 37 and 38 the center of the stroke of the distributor can be displaced to one side or the other as required.

The period of the 4 The direction of movement of the frame can be i quired for instance for levelling the surface of the material in the furnace.

If desired one or -both of the pairs of wheels 17-18 and 23-24 can be made adjustable in the vertical direction relative to the frame for adjusting the inclination of the cylinder.

The direction of rotation of the cylinder is reversible which is useful for levelling the surface. Because of the rotation of the cylinder the material is thrown out side.- ways in the direction of rotation and thus tends to accumulate more to this side than to the other. This tendency can be compensated to a great extent by suitably locating the center of the stroke of the distributor but if this is not sufficient the direction of rotation of the cylinder can be reversed for the necessary period of time.

We claim:

4. Charging apparatus according to claim 1, wherein the cylinder is mounted on amobile carriage, and wherein the said traversing means comprises mechanism for reciprocating the carriage with yand axially of the cylinder over the top of the furnace to effect the said traverse.

5. Charging apparatus according to claim 4, wherein the conveyer comprises a belt conveyer unit aligned with the cylinder and movable with said carriage, the belt conveyer unit having its discharge end extending into the intake end of the cylinder, and feeding the said pellets to the latter.

6. A charging apparatus according to claim 4 characterized thereby that the carriage is movable in a direction lengthwisel of the cylinder and carries -a pair of rotatable rollers for supporting each end of the cylinder, the rollers of at least one of said pairs being adjustable on the carriage for adjusting the inclination of the cylinder. 7. A charging apparatus according to claim 4, including ridge-shaped distributor located beneath the outlet end of the' cylinder and movable with the latter.

8. A charging apparatus according to claim 7, wherein the distributor is perforated.

9. A charging apparatus according to claim 7, includ- 5 ing means for moving the distributor in a direction side- A in the amplitude of thesidewise stroke of the distributor is adjustable.

: 12. A charging apparatus according to claim 9, including means for altering the location of the middle of the stroke of the distributor.

1. In apparatus for charging pelletizing furnaces with I terized by means for adjusting the inclination of the axis of 4 the cylinder relative to the horizontal plane. Y

3. A charging apparatus according to claim 1, characterized thereby that the direction of rotation of the cylinder is reversible.

, 13. A charging apparatus according to claim 9, wherein the driving meansv for causing reciprocation of the carriage in the direction axially of the cylinder and the means for causing the oscillation of the distributor are related so that the cycle of the oscillation of the distributor is an uneven function of the cycle of the reciprocation of the carriage.

References Cited in the le of this patent UNITED STATES PATENTS Germany Mar. 1l, 1914 

